UPF-7

Mike, Can you tell me what engine/prop combo was used on the Ultimate that is featured on the OMP website video? (My apologies if this question has already been asked.)

STLPilot

My Feedback: (21)

Believe it or not that was an MDS .68.

AFSalmon

My Feedback: (3)

Yes, the original bipe was the MDS .68 although I hate to say that plane was a total loss including my trusty old MDS .68 when radio failure caused a near full in pile driver to the pavement. My current bipe has the OS .91 installed and this rockets the plane. I rarely use more than 1/2 power. If you look at the specs almost all .91 engines are the same size and weight as their .61 counterparts.

f3a05

Hello Mike
I've almost finished building the OMP Ultimate Bipe, and intend to use the OS 91 also.
Just two queries:
[1] I'm an experienced F3A flyer, but just starting to play around with 3D.
Should I begin with the recommended C of G, or could I move it back a little?
I'd like to avoid drilling too many alternative sets of engine mount holes if possible.
[2] Please don't take this as implied criticism, but the stab and fin look a bit flimsy for high g manouevres [intended or otherwise!] Do you think it wise to wire-brace from the stab ends to near the fin top, and from the fuselage bottom to the stab ends?
Thanks for a FUN design, looking forward to your reply, and to flying the beast!

AFSalmon

My Feedback: (3)

Hey no problem! Start with the recommended cg location. I am surprised you picked the Ultimate if you are just learning 3d. The Ultimate is not a beginner 3d plane, it's very responsive and agile in the air......much like most short bipes out there. My current Ultimate does have the OS 91 on board as it's the same size and weight as the 60. I fly around at mostly 1/4 to 1/2 throttle. The tail has been fine so far and we haven't had any reported failures. Without seeing your particular stab, wood, and glue joints, I can only say use your best judgement. A bipe looks cool with tail wires anyway but if I was to do it I'd simply glue in some small carbon fiber rods like what you see on the shock flyers. Light and stiff!

As far as mounting the engine, strap that bad boy on with a rubber band or tape to set your balance. Make sure you have the rest of the gear installed and tweak from there.

AFSalmon

My Feedback: (3)

Oh as a side note for all those with backordered Ultimates:

The ast kit run was sold out probably a month or so ago and the next kit run will begin next week. All parts have been received and backorders will be filled starting next week.